I have a brand new macbook charger that's still in it's plastic wrap for sale (no box, but never used). I received it from the Apple store this weekend.

It comes with an extension cord and is identical to the product here: http://store.apple.com/us/product/MC556LL/B/apple-85w-magsafe-power-adaptor-for-15-and-17-inch-macbook-pro?fnode=5a.

Buying it new from the Apple store costs $79, not including tax. I'll selling it for half price at $40 because I don't need the charger and have extras.